Facebook (FB) slips 25 cents to $18.96 and put buyers are active in the stock right out of the gate Monday. 20,000 contracts traded in the first 5 min, or more than 5X the number of calls on the tape. About two-thirds of the activity is in the November contracts that expire at the end of this week. Nov 20s are the most actives. 3,800 so far. Dec 15 puts are also seeing some interest. 3,500 changed hands. Increased put activity might be a play on the expiration of IPO lockup periods, which includes 1.2 billion shares on 11/14. The company is also presenting a 15th Annual Africa Com 2012 conference tomorrow.

Frederic Ruffy is a well-known trader, writer, and strategist who has spent years educating investors and creating intelligent, insightful, unbiased market observations that are frequently cited by the Wall Street Journal and other financial publications. As senior analyst, Fred provides frequent and regular notes and daily updates for activity of interest.